A Prince George's County proposal to increase the tax on business property there won the reluctant approval today of a key House committee. But even the Prince George's delegates who supported the measure said the county should not expect any more financial help from the General Assembly this year.

The bill, which would generate $10 million and is critical to County Executive Parris N. Glendening's plan to erase the county's $32 million revenue gap, passed the House Ways and Means Committee by a 17-to-3 vote. Glendening has said he needs at least $15 million to avoid having to lay off 400 county employes this year.

"It was the most misleading 17-to-3 vote I've ever seen," said committee vice chairman Gerard F. Devlin (D-Prince George's), who began early lobbying his collegues to support the measure. "Nobody likes the bill. The bill itself has virtually no support. They were voting because they felt sorry for Prince George's."

"People were voting with their right hand and holding their noses with their left," said Del. Thomas Mooney (D-Prince George's). "It was Pyrrhic victory at best for Glendening. I don't think we can get anything else out of them."

Mooney added, "I think the clear message is that future willingness to help out Prince George's county is nil. The reservoir of good will is running upon a political drought."

Delegates who supported the measure, which will primarily affect utilities, said it would result in an increase in consumers utility costs.

The committee's lopsided approval of the bill came only after delegates tacked on an amendment to assure that any utility rate increases fall totally on Prince George's residents. Another amendment would limit the county's new taxing authority to one year.

Other members voiced fears that similarly cash-strapped localities may come here next year seeking similar taxing authority.

"It's setting a bad precedent," said Del. A. Wade Kach (R-Baltimore County), who voted against the measure. "You're taxing through your utility bills, in essence. You're not taxing up front. I understand their problems with the TRIM amendment, but if we do it this year, who's going to come to us next year?" TRIM is a strict limit on county property taxes that the voters have refused to modify.

The bill now goes to an uncertain fate before the full House, but supporters predicted passage there would be easier, since it is now essentially a purely local matter.

Any new business property taxes are estimated to fall almost entirely on utility firms, because they own 70 percent of the business property in the county. The delegates expect that the utilities will most likely pass on any additional tax to customers, in the form of higher gas, electricity and telephone rates. "Come on," Mooney said, "all we're doing is raising rates."

But ultimately in the eyes of the committee, it was concern over county services that won out. "Granted the citizens got themselves in trouble with TRIM," said Del. Mary Boergers (D-Montgomery), "But I think the county is at a critical point. The county is going to deteriorate if they can't supply services to their citizens."